1/* Work around platform bugs in stat. 2 Copyright (C) 2009-2022 Free Software Foundation, Inc. 3 4 This file is free software: you can redistribute it and/or modify 5 it under the terms of the GNU Lesser General Public License as 6 published by the Free Software Foundation; either version 2.1 of the 7 License, or (at your option) any later version. 8 9 This file is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17/* Written by Eric Blake and Bruno Haible. */ 18 19/* If the user's config.h happens to include <sys/stat.h>, let it include only 20 the system's <sys/stat.h> here, so that orig_stat doesn't recurse to 21 rpl_stat. */ 22#define __need_system_sys_stat_h 23#include <config.h> 24 25/* Get the original definition of stat. It might be defined as a macro. */ 26#include <sys/types.h> 27#include <sys/stat.h> 28#undef __need_system_sys_stat_h 29 30#if defined _WIN32 && ! defined __CYGWIN__ 31# define WINDOWS_NATIVE 32#endif 33 34#if !defined WINDOWS_NATIVE 35 36static int 37orig_stat (const char *filename, struct stat *buf) 38{ 39 return stat (filename, buf); 40} 41 42#endif 43 44/* Specification. */ 45#ifdef __osf__ 46/* Write "sys/stat.h" here, not <sys/stat.h>, otherwise OSF/1 5.1 DTK cc 47 eliminates this include because of the preliminary #include <sys/stat.h> 48 above. */ 49# include "sys/stat.h" 50#else 51# include <sys/stat.h> 52#endif 53 54#include "stat-time.h" 55 56#include <errno.h> 57#include <limits.h> 58#include <stdbool.h> 59#include <string.h> 60#include "filename.h" 61#include "malloca.h" 62#include "verify.h" 63 64#ifdef WINDOWS_NATIVE 65# define WIN32_LEAN_AND_MEAN 66# include <windows.h> 67# include "stat-w32.h" 68/* Don't assume that UNICODE is not defined. */ 69# undef WIN32_FIND_DATA 70# define WIN32_FIND_DATA WIN32_FIND_DATAA 71# undef CreateFile 72# define CreateFile CreateFileA 73# undef FindFirstFile 74# define FindFirstFile FindFirstFileA 75#endif 76 77#ifdef WINDOWS_NATIVE 78/* Return TRUE if the given file name denotes an UNC root. */ 79static BOOL 80is_unc_root (const char *rname) 81{ 82 /* Test whether it has the syntax '\\server\share'. */ 83 if (ISSLASH (rname[0]) && ISSLASH (rname[1])) 84 { 85 /* It starts with two slashes. Find the next slash. */ 86 const char *p = rname + 2; 87 const char *q = p; 88 while (*q != '\0' && !ISSLASH (*q)) 89 q++; 90 if (q > p && *q != '\0') 91 { 92 /* Found the next slash at q. */ 93 q++; 94 const char *r = q; 95 while (*r != '\0' && !ISSLASH (*r)) 96 r++; 97 if (r > q && *r == '\0') 98 return TRUE; 99 } 100 } 101 return FALSE; 102} 103#endif 104 105/* Store information about NAME into ST. Work around bugs with 106 trailing slashes. Mingw has other bugs (such as st_ino always 107 being 0 on success) which this wrapper does not work around. But 108 at least this implementation provides the ability to emulate fchdir 109 correctly. */ 110 111int 112rpl_stat (char const *name, struct stat *buf) 113{ 114#ifdef WINDOWS_NATIVE 115 /* Fill the fields ourselves, because the original stat function returns 116 values for st_atime, st_mtime, st_ctime that depend on the current time 117 zone. See 118 <https://lists.gnu.org/r/bug-gnulib/2017-04/msg00134.html> */ 119 /* XXX Should we convert to wchar_t* and prepend '\\?\', in order to work 120 around length limitations 121 <https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file> ? */ 122 123 /* POSIX <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13> 124 specifies: "More than two leading <slash> characters shall be treated as 125 a single <slash> character." */ 126 if (ISSLASH (name[0]) && ISSLASH (name[1]) && ISSLASH (name[2])) 127 { 128 name += 2; 129 while (ISSLASH (name[1])) 130 name++; 131 } 132 133 size_t len = strlen (name); 134 size_t drive_prefix_len = (HAS_DEVICE (name) ? 2 : 0); 135 136 /* Remove trailing slashes (except the very first one, at position 137 drive_prefix_len), but remember their presence. */ 138 size_t rlen; 139 bool check_dir = false; 140 141 rlen = len; 142 while (rlen > drive_prefix_len && ISSLASH (name[rlen-1])) 143 { 144 check_dir = true; 145 if (rlen == drive_prefix_len + 1) 146 break; 147 rlen--; 148 } 149 150 /* Handle '' and 'C:'. */ 151 if (!check_dir && rlen == drive_prefix_len) 152 { 153 errno = ENOENT; 154 return -1; 155 } 156 157 /* Handle '\\'. */ 158 if (rlen == 1 && ISSLASH (name[0]) && len >= 2) 159 { 160 errno = ENOENT; 161 return -1; 162 } 163 164 const char *rname; 165 char *malloca_rname; 166 if (rlen == len) 167 { 168 rname = name; 169 malloca_rname = NULL; 170 } 171 else 172 { 173 malloca_rname = malloca (rlen + 1); 174 if (malloca_rname == NULL) 175 { 176 errno = ENOMEM; 177 return -1; 178 } 179 memcpy (malloca_rname, name, rlen); 180 malloca_rname[rlen] = '\0'; 181 rname = malloca_rname; 182 } 183 184 /* There are two ways to get at the requested information: 185 - by scanning the parent directory and examining the relevant 186 directory entry, 187 - by opening the file directly. 188 The first approach fails for root directories (e.g. 'C:\') and 189 UNC root directories (e.g. '\\server\share'). 190 The second approach fails for some system files (e.g. 'C:\pagefile.sys' 191 and 'C:\hiberfil.sys'): ERROR_SHARING_VIOLATION. 192 The second approach gives more information (in particular, correct 193 st_dev, st_ino, st_nlink fields). 194 So we use the second approach and, as a fallback except for root and 195 UNC root directories, also the first approach. */ 196 { 197 int ret; 198 199 { 200 /* Approach based on the file. */ 201 202 /* Open a handle to the file. 203 CreateFile 204 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-createfilea> 205 <https://docs.microsoft.com/en-us/windows/desktop/FileIO/creating-and-opening-files> */ 206 HANDLE h = 207 CreateFile (rname, 208 FILE_READ_ATTRIBUTES, 209 FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, 210 NULL, 211 OPEN_EXISTING, 212 /* FILE_FLAG_POSIX_SEMANTICS (treat file names that differ only 213 in case as different) makes sense only when applied to *all* 214 filesystem operations. */ 215 FILE_FLAG_BACKUP_SEMANTICS /* | FILE_FLAG_POSIX_SEMANTICS */, 216 NULL); 217 if (h != INVALID_HANDLE_VALUE) 218 { 219 ret = _gl_fstat_by_handle (h, rname, buf); 220 CloseHandle (h); 221 goto done; 222 } 223 } 224 225 /* Test for root and UNC root directories. */ 226 if ((rlen == drive_prefix_len + 1 && ISSLASH (rname[drive_prefix_len])) 227 || is_unc_root (rname)) 228 goto failed; 229 230 /* Fallback. */ 231 { 232 /* Approach based on the directory entry. */ 233 234 if (strchr (rname, '?') != NULL || strchr (rname, '*') != NULL) 235 { 236 /* Other Windows API functions would fail with error 237 ERROR_INVALID_NAME. */ 238 if (malloca_rname != NULL) 239 freea (malloca_rname); 240 errno = ENOENT; 241 return -1; 242 } 243 244 /* Get the details about the directory entry. This can be done through 245 FindFirstFile 246 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfilea> 247 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> 248 or through 249 FindFirstFileEx with argument FindExInfoBasic 250 <https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-findfirstfileexa> 251 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ne-minwinbase-findex_info_levels> 252 <https://docs.microsoft.com/en-us/windows/desktop/api/minwinbase/ns-minwinbase-_win32_find_dataa> */ 253 WIN32_FIND_DATA info; 254 HANDLE h = FindFirstFile (rname, &info); 255 if (h == INVALID_HANDLE_VALUE) 256 goto failed; 257 258 /* Test for error conditions before starting to fill *buf. */ 259 if (sizeof (buf->st_size) <= 4 && info.nFileSizeHigh > 0) 260 { 261 FindClose (h); 262 if (malloca_rname != NULL) 263 freea (malloca_rname); 264 errno = EOVERFLOW; 265 return -1; 266 } 267 268# if _GL_WINDOWS_STAT_INODES 269 buf->st_dev = 0; 270# if _GL_WINDOWS_STAT_INODES == 2 271 buf->st_ino._gl_ino[0] = buf->st_ino._gl_ino[1] = 0; 272# else /* _GL_WINDOWS_STAT_INODES == 1 */ 273 buf->st_ino = 0; 274# endif 275# else 276 /* st_ino is not wide enough for identifying a file on a device. 277 Without st_ino, st_dev is pointless. */ 278 buf->st_dev = 0; 279 buf->st_ino = 0; 280# endif 281 282 /* st_mode. */ 283 unsigned int mode = 284 /* XXX How to handle FILE_ATTRIBUTE_REPARSE_POINT ? */ 285 ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? _S_IFDIR | S_IEXEC_UGO : _S_IFREG) 286 | S_IREAD_UGO 287 | ((info.dwFileAttributes & FILE_ATTRIBUTE_READONLY) ? 0 : S_IWRITE_UGO); 288 if (!(info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) 289 { 290 /* Determine whether the file is executable by looking at the file 291 name suffix. */ 292 if (info.nFileSizeHigh > 0 || info.nFileSizeLow > 0) 293 { 294 const char *last_dot = NULL; 295 const char *p; 296 for (p = info.cFileName; *p != '\0'; p++) 297 if (*p == '.') 298 last_dot = p; 299 if (last_dot != NULL) 300 { 301 const char *suffix = last_dot + 1; 302 if (_stricmp (suffix, "exe") == 0 303 || _stricmp (suffix, "bat") == 0 304 || _stricmp (suffix, "cmd") == 0 305 || _stricmp (suffix, "com") == 0) 306 mode |= S_IEXEC_UGO; 307 } 308 } 309 } 310 buf->st_mode = mode; 311 312 /* st_nlink. Ignore hard links here. */ 313 buf->st_nlink = 1; 314 315 /* There's no easy way to map the Windows SID concept to an integer. */ 316 buf->st_uid = 0; 317 buf->st_gid = 0; 318 319 /* st_rdev is irrelevant for normal files and directories. */ 320 buf->st_rdev = 0; 321 322 /* st_size. */ 323 if (sizeof (buf->st_size) <= 4) 324 /* Range check already done above. */ 325 buf->st_size = info.nFileSizeLow; 326 else 327 buf->st_size = ((long long) info.nFileSizeHigh << 32) | (long long) info.nFileSizeLow; 328 329 /* st_atime, st_mtime, st_ctime. */ 330# if _GL_WINDOWS_STAT_TIMESPEC 331 buf->st_atim = _gl_convert_FILETIME_to_timespec (&info.ftLastAccessTime); 332 buf->st_mtim = _gl_convert_FILETIME_to_timespec (&info.ftLastWriteTime); 333 buf->st_ctim = _gl_convert_FILETIME_to_timespec (&info.ftCreationTime); 334# else 335 buf->st_atime = _gl_convert_FILETIME_to_POSIX (&info.ftLastAccessTime); 336 buf->st_mtime = _gl_convert_FILETIME_to_POSIX (&info.ftLastWriteTime); 337 buf->st_ctime = _gl_convert_FILETIME_to_POSIX (&info.ftCreationTime); 338# endif 339 340 FindClose (h); 341 342 ret = 0; 343 } 344 345 done: 346 if (ret >= 0 && check_dir && !S_ISDIR (buf->st_mode)) 347 { 348 errno = ENOTDIR; 349 ret = -1; 350 } 351 if (malloca_rname != NULL) 352 { 353 int saved_errno = errno; 354 freea (malloca_rname); 355 errno = saved_errno; 356 } 357 return ret; 358 } 359 360 failed: 361 { 362 DWORD error = GetLastError (); 363 #if 0 364 fprintf (stderr, "rpl_stat error 0x%x\n", (unsigned int) error); 365 #endif 366 367 if (malloca_rname != NULL) 368 freea (malloca_rname); 369 370 switch (error) 371 { 372 /* Some of these errors probably cannot happen with the specific flags 373 that we pass to CreateFile. But who knows... */ 374 case ERROR_FILE_NOT_FOUND: /* The last component of rname does not exist. */ 375 case ERROR_PATH_NOT_FOUND: /* Some directory component in rname does not exist. */ 376 case ERROR_BAD_PATHNAME: /* rname is such as '\\server'. */ 377 case ERROR_BAD_NET_NAME: /* rname is such as '\\server\nonexistentshare'. */ 378 case ERROR_INVALID_NAME: /* rname contains wildcards, misplaced colon, etc. */ 379 case ERROR_DIRECTORY: 380 errno = ENOENT; 381 break; 382 383 case ERROR_ACCESS_DENIED: /* rname is such as 'C:\System Volume Information\foo'. */ 384 case ERROR_SHARING_VIOLATION: /* rname is such as 'C:\pagefile.sys' (second approach only). */ 385 /* XXX map to EACCES or EPERM? */ 386 errno = EACCES; 387 break; 388 389 case ERROR_OUTOFMEMORY: 390 errno = ENOMEM; 391 break; 392 393 case ERROR_WRITE_PROTECT: 394 errno = EROFS; 395 break; 396 397 case ERROR_WRITE_FAULT: 398 case ERROR_READ_FAULT: 399 case ERROR_GEN_FAILURE: 400 errno = EIO; 401 break; 402 403 case ERROR_BUFFER_OVERFLOW: 404 case ERROR_FILENAME_EXCED_RANGE: 405 errno = ENAMETOOLONG; 406 break; 407 408 case ERROR_DELETE_PENDING: /* XXX map to EACCES or EPERM? */ 409 errno = EPERM; 410 break; 411 412 default: 413 errno = EINVAL; 414 break; 415 } 416 417 return -1; 418 } 419#else 420 int result = orig_stat (name, buf); 421 if (result == 0) 422 { 423# if REPLACE_FUNC_STAT_FILE 424 /* Solaris 9 mistakenly succeeds when given a non-directory with a 425 trailing slash. */ 426 if (!S_ISDIR (buf->st_mode)) 427 { 428 size_t len = strlen (name); 429 if (ISSLASH (name[len - 1])) 430 { 431 errno = ENOTDIR; 432 return -1; 433 } 434 } 435# endif /* REPLACE_FUNC_STAT_FILE */ 436 result = stat_time_normalize (result, buf); 437 } 438 return result; 439#endif 440} 441